William haddef



iUNiTED STATES ArENr @rricn.

WILLIAM HADDEN, OF NEW YORK, N. Y.

DUPLEX TELEGRAPH.

SPECIFICATION forming part of Letters Patent No. 228,458, dated June 8, 1880.

Application filed September 8, 1879.

To all whom it may concern:

Be it known that I, WILLIAM HADDEN, of New York, in the county of New York and State of New York, have invented a new and Improved System of Duplex or Double-Sending Telegraph, of which the following is a specification.

Figure 1 is a plan view of my improved sys tem. Fig. 2 is a side view of one of the keys. Fig. 3 is a side view of the other key.

Similar letters of reference indicate corresponding parts.

The object of this invention is to furnish an improved telegraph system for sending and receiving two sets of signalsin the same direction on one wire at the same time.

The invention consists in the combination of two keys, two polarized relays, and their local circuitsand sounders, for the purpose of trans mittingcurrents of either polarity by the operation of the keys separately, and a currentreversing apparatus for sending an alternate current when both keys are simultaneously depressed. The non-alternating current of one polarity affects one of the two polarized relays in the circuit, and the non-alternating'curreut.

of the opposite polarity affects the other polarized relay in the circuit, and the alternating current simultaneously affects both of the polarized relays in the circuit.

The object of the invention is to provide means for sending and receiving two sets of signals over one wire at the same time without confusion or interference.

Referring to the drawings, K K are two telegraphic keys of ordinary construction. B is the main-line battery. I O is the inductioncoil, used for sending an alternating current. It R are two polarized relays, and B B are the two local batteries connected with the sounders S S and under the control of the relays R R. B is theinduction-coil battery. All of these parts are constructed in the usual way.

The polarized relays are always in the main line, and when the line is at rest both of its ends are connected with the earth, the mainline battery B being cut out. \Vhen the key K is depressed the contact-point a and the insulated contact-point a are separated, and a circuit from the earth through the key K and the main-line battery Bis completed through the contact-spring a the wires 1 2, the coutact-points b b, and wire 3 on one side of the battery, and the wires 4 5, contact'point 11 key K and wire 6 on the opposite side of the battery, and thus to the line. By this means an impulse of one polarity is sent through the two relays It R affecting only one of them, however, as the free ends of the tongues of the relays are of opposite polarity; or, if the tongues are alike in respect to polarity, the magnets are wound in opposite directions.

hen the key K is depressed the contactpoints I) b are separated, and a circuit through the main-line battery B and the key K is completed from the earth through the wire 9, contact-spring a, insulated eontact-pointa, and wire 4 to the battery; thence through the wire 3, the key K the pivot of the key K and the wire 6, through the line. By this means an impulse of the opposite polarity from that sent by the key K is sent through the relays R R affecting the relay that before was quiet.

When the keys K K are depressed simultaneously the batteryB is cut out of the main line, and the current from the secondary coil of the induction-coil I O is made to traverse the main line and pass through the polarized relays R B In this case the two keys perform the part of a single key, sending the alternating currents through the circuit, so as to give the desired signals. The secondary current (which is always alternating in polarity direction) is generated continually by the opening and closing of the primary circuit of the induction-coil by-means of an ordinary interrupter; Therefore, when the keys are depressed in the manner described, an alternating current passes through both of the relays and affects them alike. The course of the secondary current, tracing it through the key K from the earth, is through the spring a wire 1, the wire 7, the induction-coil, the wire 8, contact-spring b, the key K and its pivots, to the wire earth.

When key K is depressed a current from the negative pole of the main-line battery B (or the positive pole, accordingly as the battery 6, thence through the relays to the may be connected) traverses the main line, and will afl'ect only one of the polarized re1ays say R, for example.

\Vhen the keyK is depressed a eurrentfrom the main-line battery B, of the opposite polarity from that sent by the key K traverses the line and will only affect the other relay--say R, which was not moved by the current from the key K. Thus the armatures of the relays R R move only on the depression of the keys which control their action.

When the keys K K are both depressed simultaneously the main-line battery B is cut out of the main line, and the positive and negative impulses of the secondary current, proceeding from the inductioircoil I O, which is now in the mainline circuit, are sent through the relays R R causing the arinatures of both to vibrate in unison with the interrupter of the primary current of the induction-coil l O, the

primary current of the induction-coil beingiu constant operation.

I do not propose to limit the combination to the use of an induction-coil for producing an alternating current, as I prefer to use some other mechanical apparatus to produce the same or a better result. I simply use the induction-coil in the combination to illustrate the principle of operation.

The action of the relays It R and their respective sounders S S in combination with the keys K K is as follows: When the line is at rest the circuit D of the local battery of each relay is through the tongue of the said relay and its contactpoints c c, and therefore the current does not affect its sounder by reason of the resistance in that part of the circuitthat is,in the bobbins of the sounders. When, however, the tongue of either relay is thrown over so as to separate the contact-points 0 c, then thelocal battery will act upon the sounder, the current being through the circuit E. This will also be the case when the tongues of the relays are caused to vibrate rapidly under the influence of an alternating current from the induction-coil I O, which will occur when both keys K K are pressed down at the same time.

It will be seen from this series of actions of keys, relays, main-line battery and other batteries, and the alternating current that two distinct and separate series of signals may be transmitted over one wire and received by the relays at the other end of the line without confusion or interference at the same time.

Having thus described my invention, 1 claim as new and desire to secure by Letters Patent- The combination of an unreversed or direct current 01" one polarity to affect one of two p0 larized relays in the circuit, and an unrey ersed or direct current of the opposite polarity to atfect another polarized relayin the circuit, and an alternating current to simultaneously affect two polarized relays in the circuit, for the purpose of sending and receiving two sets of signals over one wire at the same time without con fusion orinterference, substantially as herein shown and described.

'WILLIAM HADDEN.

Witnesses:

JAMES T. GRAHAM, O. Snnewrcic. 

